Help - 07 GMC 5500 steering wander after FE rebuild

[Sticks]

Had to replace the front springs, kingpins, drag link, wheel bearings, shocks, tires, and brakes on a truck at work. The truck unloaded was riding hard on the bump stops and the tires were cupped something fierce. Front axle is an 8000# beam type.



Got done, took for a test drive and made it a whopping 1 block before I chose to return to the shop.



30* of steering wander to either side (READ - start drifting left, you have to turn about 30* to the right before the truck responds, then correct 30* to the left cause you are now going to the right), and wheels will not return to center after a hard turn. Made for a wild ride.



Checked for anything and everything that I could think of. Tie rod ends are good, toe in is approx 1/8", the springs are not drifting, nor is the axle drifting on the springs. The track bar however is flexing up/down when you start to turn the wheel before the wheels turn. One thing is, after the kingpin replacement, they are stupid tight. You can not move them by hand.



My coworker at the shop said he has done class 8 trucks that had tighter kingpins than this one after replacement and did not have this issue.



The caster may hosed (return to center) if it had been taken in for alignment in the last few years, and I can't see camber being the problem for wander.



Took it back out and did 1 mile of full left to right turns @ 5-10mph to try to break in the kingpins a bit. It either helped, or I started getting used to the wander.



Steering diagnostics is not my strong suit, especially if it is not obvious what or where the culprit may be. Really at a loss on this one.



Suggestions anyone?

 

[mwilson]

Sounds like a tight kingpin to me. You may have boogered a bushing while driving it in. Or they were not reamed properly if that was required.



It can be confusing for techs whether the kingpin kit has bushings that need to be reamed after they are installed. Meritor, for example offers three different kingpin sets for each of the various popular front axles. Two of those kits have bushings that are required to be reamed and one does not.



The Class 8 trucks have heavier everything and would be more forgiving of a tight pin than the little 5500.



Jack it up, unhook the tie rod and move the knuckles by hand. The alxe beam itself could be wallowed out if the kingpins were really gone and the axle beam may have to be sleeved at a machine shop.



It is not right, that's for sure. Sounds like it will need to come apart again.



Mike.

 

[Sticks]

Yup, gotta ream the bushings, of which we do not have a reamer.

Gonna try a different set.

I hate doing things twice.

 

[mwilson]

Yup, gotta ream the bushings, of which we do not have a reamer.



Gonna try a different set.



I hate doing things twice.

It happens.



If you were closer I would lend you a ream.



Mike.

 

[Sticks]

Got the old ones pressed out and a new set in. Much better now. Still a bit of steering wander, but nowhere near the pucker power it was before.

Goes in for alignment next week then it's outta my hair.

Note to self - don't order any more kingpin kits that require reaming... .

Mike - Thank you for the offer and help. Much appreciated.

 

[mwilson]

This is the newest design for a front axle, see how the kingpin is fixed to the axle and the knuckle separates?

I've only seen one beam that needed to be replaced so far.

Go down several pages and look at the parts diagram.

http://www.hendrickson-intl.com/CMSPages/GetFile.aspx?guid=8f8d8325-3dfb-4527-a7e5-b0cefeb4e02a

Mike.